The Very Large Telescope is celebrating its 15th birthday

The celestial eye on Paranal is still the most modern optical telescope in the world

The Star Cradle IC 2944, taken from the VLT of the ESO © ESO
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It has been doing its job for 15 years now - and is still the world's most advanced optical telescope: the Very Large Telescope (VLT) on Paranal Chile. On May 25, 1998, the first of the four major telescopes at this Observatory of the European Southern Observatory (ESO) had its "First Light". To celebrate the anniversary, ESO has released a special gem from the enormous amount of fascinating VLT footage: The Star Cradle IC 2944. This nursery of new stars has never before been captured so sharply by an earth-based telescope as the VLT.

Interstellar dust and gas clouds are the nurseries where stars are born and grow. The new picture shows one of them, IC 2944. It appears as a gently glowing, reddish background. This shot is the sharpest ever made of this object from Earth. The cloud is about 6, 500 light years away from us in the southern constellation Centaurus. This part of the sky is home to many similar nebulae, which are thoroughly studied by astronomers to explore the mechanism of star formation.

Cold lumps as precursors of stars

Emission nebulae like IC 2944 consist mainly of hydrogen gas, which shines in a characteristic shade of red. This glow is caused by the intense radiation emanating from the many bright, newborn stars. Strange, dark lumps of opaque dust are visible against this bright backdrop. These cold clouds are known as Bok-globules. They are named after the Dutch-American astronomer Bart Bok, who was the first to draw attention to them in the 1940s, as they came into question as possible sites of star formation.

Bigger Bok globules easily collapse and produce new stars, provided they are in an undisturbed location. The globules in this picture, however, are under heavy fire, as it were, by the UV radiation from nearby hot, young stars. They are both eroded and fragmented, much like pieces of butter thrown into a hot pan. In all likelihood, these globules in the star cradle IC 2944 will be destroyed before they can collapse and form stars.

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Sharp look through cosmic clouds

Examining Bok globules is usually not easy as they are opaque to visible light. This makes it difficult for astronomers to observe their internal processes, so that other means are needed to reveal their secrets. The tools for this are observations in the infrared and submillimeter range of the electromagnetic spectrum. In this wavelength range, for example, dust clouds light up, whose temperature is only a few degrees above the absolute zero point.

This celestial region was mapped earlier by NASA's Hubble Space Telescope. On Earth, however, this new image of the FORS instrument on the Very Large Telescope is the bijourster of this star cradle. It also covers a larger section of the sky than Hubble and thus shows the entire star formation landscape at a glance.

Among other things, the great power of the VLT is due to the fact that its four large telescopes, equipped with numerous special instruments, have since 1998 been supplemented by four auxiliary telescopes, all of which together contain the VLT Interferometer (VLTI) ) form. Through a computer-controlled interconnection of all telescopes, astronomers can virtually turn them into one large telescope key - and thus achieve greater resolutions than with each telescope individually.

(ESO / Max Planck Institute for Astronomy, 24.05.2013 - NPO)